To what extent was the Royalist defeat in the English Civil War due to Charles I's weak leadership?

When trying to answer a 45 mark A2 level question it is crucial to establish your argument from the outset, so that it remains clear throughout your essay. For this question the student is being asked to examine the factors that contributed to the Royalist defeat in the Civil War, and to judge whether Charles I's leadership can be said to be the most important one. Personally I would argue that it was Charles' leadership that resulted in his defeat, with his lack of political acumen leaving the Royalists unable to counter the increasing strength the New Model Army and their control of London gave Parliament. The two sides were evenly matched at the outbreak of war in 1642, but Charles' failure to exploit Royalist advantages meant Parliament was able to take the upper hand. With that being my overall argument, I still have to ensure that I am presenting the 'balanced' argument that the A2 mark scheme wants. A 'balanced' argument essentially means that you have to assess other factors and demonstrate why your argument is more valid. For this question some of the other factors to consider are the strengths of the New Model Army and the importance of Parliament holding London. In terms of structure I would assess these two factors after my introduction and then state 'However these two Parliamentary strengths were exacerbated by the weaknesses of Charles' leadership, and therefore it was this leadership that ultimately resulted in Royalist defeat...' and go on to give evidence of this. For A2 essays don't forget to include historiography as this is another key aspect of the mark scheme that ensures you are hitting the top level marks.